The present invention relates to an electric connector for a connecting unit having a large number of ways, and particularly, but not exclusively, for a connecting unit of the type used to connect an electronic central control unit to a vehicle electric system.
Electric connecting units are known which substantially comprise a plug connector having a number of electric terminals; and a socket connector having a number of complementary electric terminals cooperating with respective electric terminals of the plug connector when the two connectors are mated. In the example application mentioned above, the plug connector is connected to a bundle of cables forming part of the vehicle wiring, while the socket connector is conveniently integrated in the central control unit.
As is known, the force required to mate the connectors increases in direct proportion to the number of electric terminals of the connectors, and, in fact, mainly equals the sum of the forces required to insert each of the terminals inside the respective complementary terminal.
Electric connecting units are known which comprise a lever device for reducing the manual force required and ensuring accurate guidance to mate the connectors.
EP-A-0 363 804 illustrates a connecting unit featuring such a device, and wherein one of the two connectors carries a slide movable in a transverse direction with respect to the connection direction and having cam slots cooperating with respective engaging pins carried by the other connector to produce a relative translation between the connectors in the relative engagement direction in response to translation of the slide in said transverse direction.
A lever hinged to the body of the first connector and connected to the slide provides for translating the slide and so reducing the force required to mate the connectors.
Known lever devices of the type briefly described above have several drawbacks.
In particular, to effectively reduce the force required, the resisting arm of the lever, i.e. the distance between the fixed hinge axis of the lever and the point of application of the thrust transmitted to the slide, must be conveniently small with respect to the power arm of the lever. On the other hand, a short resisting arm results in a small amount of translation of the slide and, hence, in an unfavourable transmission of forces between the slide and the other connector.
Alternatively, the efficiency of the lever device may be improved by increasing the length of the power arm or the angular travel of the lever. Such dimensions, however, being governed by overall size considerations, can only be increased to a certain extent.
Moreover, connection of the lever as described above results in severe frictional forces which considerably increase the manual force required to activate the lever.
It is an object of the present invention to provide an electric connector for a connecting unit of the type described above, designed to eliminate the aforementioned drawbacks typically associated with known connecting units.
According to the present invention, there is provided an electric connector of the type comprising an insulating casing having a number of cavities for respective electric terminals extending in a connection direction of said connector to a complementary connector; and a lever device for reducing the force required for connection to said complementary connector; said lever device comprising a slide sliding with respect to said casing in a direction perpendicular to said connection direction and having cam means interacting with said complementary connector to generate a force for mating said connectors in response to translation of said slide; and an activating lever for activating said slide and connected to the slide by first articulated connecting means, and to said casing by second articulated connecting means;
characterized in that both said first and said second articulated connecting means comprise a pair of hinge elements connected to each other in sliding manner to impart a translatory component of motion to said activating lever.